The pic below shows an older (~12 years old) pattern plane which I built and just recently started flying again. The WS is 50.5" and with an OS 25 SF, weighs ~3-3.5 lbs. The problem is the engine. The OS is also old (bought in 1989) and doesn't seem to have enough power to really pull this plane around. The main problem is on takeoff. I fly off a grass runway and with 2" wheels the plane barely gets off the ground in ~100-150ft. In the air, the plane could also use a little more umph. I was thinking of replacing the .25 with something bigger, but wasn't sure which engine would be best. Here are the choices I was considering:

1) OS .32 SX (new)- should be more than enough power, but a little pricey.

2) Thunder Tiger .36 (new)- maybe too much power?

3) an older (~12 years old) ASP .40, which is currently in my trainer plane. I like this engine, mainly because I already have it and don't have to spend any $$$, but am worried the plane may be overpowered. I suppose I could just fly it at 1/2 throttle. Since I needed a lot of lead (~3 ounces) with the .25 engine, the ASP, which weighs more might be perfect as far as balancing the plane w/o the need for more lead weight.

What are your thoughts on my above choices? Are there other engines I should consider?