I just built a slope PicoMoth to go alongside my stock PicoMoth.
Taking account of your comments about being on a budget I'd recommend you go to www.allerc.com
and get their strengthened strut kit and their 280 motor conversion, which will set you back a very few dollars. BTW whatever motor you decide, get the strengthened strut kit - its a great improvement on the flimsy plastic stock parts.
What you'll then end up with is a plane which shares the original (to me, important) PM characteristics of being incredibly slowfly and "forever" duration on a LiPo (recommended 110 NICAD is a complete PITA) but which has more authority in a breeze than the IPS powered version and which, with its little direct drive prop (comes in the motor conversion kit) looks much more scale and sounds pretty good too.
I can fly mine in a 3 foot radius circle round my head! Haven't got round to trying it in the house yet (- mind you now I think about it she's away this week - maybe this would be a good time........?)
I was worried that the 280 motor would give me a balance problem but it turned out not to, although I'm using a slightly smaller LiPo. You will need to do some foam shaping BEFORE you glue the fuselage halves together and remember not to cut too much away from the U/C supports in the same area. Try and fix it so that you have some fore and aft adjustment choice on the battery position.
You could try it with the IPS first first and then do a retro fit but the IPS uses a stick mount which you'd have to saw off because the 280 has a bulkhead type mounting.
Edit - I just checked - the strut kit was $7.95 and the motor conversion $8.66 - plus shipping