In my opinion the best pairing would be an Albino male and a Het for Albino female. The strain doesn't really matter. Sharps are more expensive and are suppose to be more colorful as adult. At the same time Kahls are less expensive and bred properly they can be just as colorful as adults. Choose what you can afford and like the best. 
Having said that.........
Please don't get boas just because you want an "INVESTMENT!!"
Get what you want because you enjoy boas. Getting boas as an investment can lead to major dissappointments. There's no gaurantee they'll ever reproduce. I do realize that if they do reproduce you can make some extra cash, but there should be more to having them than just "extra cash". Just get what you want and enjoy having them as a hobby. If you get get babies down the road, that would be AWESOME!!! There's nothing like seeing your boa give birth for the first time. It's such a RUSH!!
Anyway good luck. Hopefully some day you'll be posting pictures of you first babies. 