There's more options than you mentioned. I think one of your options is best, but I want you to at least acknowledge a few others just in case you think one is better for some reason. For sake of simplicity, I will call your first option (REC pagan/WIS orc) as Option A, your second (REC orc/INT pagan) as B, and my others as C, D, and E.
A) REC pagan and WIS orc.
B) REC orc and INT pagan.
C) REC pagan and INT orc. Here, the pagan tanks and the orc heals when necessary, but otherwise attacks.
D) REC pagan and REC orc. Here, they will do double pulls and draw them in together, killing together with Frost Barrier, Fire Thorn, and their instant AOE's.
E) INT pagan and INT orc. Here, they will both kill mobs one at a time (individually or together -- doesn't matter) similiar to 2 hunters duoing.
Now let's discuss each option for both duoing and once you start looking for parties.
A) This is the 2nd worst options because only 1 person is attacking AND it's the tank, who has low attack. When looking for parties, people will want the orc but only take the pagan as a tag along. Unless the pagan tanks for the party, they will be more harm than good because they'll pull aggro form whoever DOES tank. Please, do not do this one.
B) This is probably the BEST option, and since you thought of it yourself you should probably go with it. Oracles are in generaly better tanks due to higher natural resistance to magic, Self Heal, and the ability to use Great Healing Pool without getting to close to the other person, among possible other things I'm sure that I'm just not thinking of right now. This duo has only one drawback: none of a pagans' AOE's are spammable (while an orcs are). If you don't kill before you run out of AOE's, the kills wil go slower than if you go with option C. I'm sure this issue will come up some, but overall the pros probably outweigh this one con. When looking for a party, this will be everyone's favorite duo. They'll have a nice DPS pagan, but also a nice orc tank and what party wouldn't kill for a tank?
C) This is the next best option, and what you should do if you fear the con of option B. In general, orcs have more consistent, reliable DPS and over a long pull will deal more damage, consistently and reliably, to kill the mobs and get the job done. The problem lies in the fact that pagans are more susceptible to magic and can't heal themselves. The pagan will be relying almost entirely on the oracle to heal, and if they are busy DPSing this could pose a problem. If the DPSer has to constantly be healing or dispelling, they will clearly kill slower...making this more than likely worse than option B (whose tank can heal and dispel themselves, not wasting the time of the attacker). When looking for a party, this duo is also not very attractive. I've already mentioned the problem with REC pagans in parties...and as far as a borc goes; sure, they might not mind them in the party, BUT, they more likely need a healer -- or even a tank, before they need DPS.
D) This is 3rd best, and 3rd worst option. This is a good option if you are good at finding places to grind with lots of mobs and if you both (even the pagan) can stay alive well enough without relying on the other. The problem with this option is the same as option A: no DPSers. You are relying on Frost Barrier and Fire Thorn to kill things. This may seem fast at first, but at a high enough level it'll be fairly slow. If you try looking for a party with this duo, you'll undergo that whole "useless REC pagan" option as before, but even worse, they're completley useless since you already have an orc in your duo to tank. This is by far the worst one for parties.
E) This is the worst option, but is an option nonetheless. It's entirely different from the others as it requires no tanking. The problem is...pagans and orcs are AOE-killers, and therefore this duo would be the slowest of all. It's a good one for parties though, because you have a TWO DPSers, if need be, and if not you at least have 1 and a healer! Even so, I highly don't recomend this option.
Well, there's my opinions on duoing/partying with those 2 classes in Ep5. As far as starting in Ep4 goes...I wouldn't advise it. Both classes change drasticaly in Ep5 and what you want to do with them would probably change too. If you think you'll be getting Ep5 soon, just wait it out. It's worth the wait.
Side note: splasher_ just likes to bash everyone and make them feel bad. Play whatever class you have the most fun playing.
And if you DO deside to play a BG instead of pagan, make the orc a BORC (regardless of whatever splasher_ tells you). BG's can tank well, and don't need a tank nor do they really need a WIS healer.