7 Power Draw? I don't know how you'll have enough WPF in both. But if you insist, then do 21/18. I do fine with 137 WPF in Archery on my 8 Power Draw archer, so if you have around that should be good; then you can put the rest of the WPF points into 2h. I use up to a Long Bow on that archer and do well, so you should try it, I think.
If you want to try something different instead. Use 6 Power Draw, and try 18/21. 6 Power Draw, 6 Athletics, 7 Weapon Master, and 4 Power Strike. It may hit a little low in melee, but if you get a real two-hander and like a Strong (Horn) Bow, you should get kills if you're any good. It also works with a War/Long (Rus/Long) Bow and a Mace, Langes Messer, or Fighting Axe. I'd get 150 Archery WPF, and that leaves you with 87 2h WPF.
Also, heirloom the bow first, or if you plan on retiring multiple times, you MAY want to heirloom your arrows once and then get your bow to Masterwork, just so you have extra arrows.
