Then I'd say go with an LRP.

The For Sale listings usually have plenty of 1/12 outfits being sold off at fire-sale prices by folks who thought they had 1/10 dialed so "how tough can those simple little 1/12 cars be". Maybe find one of those?

I. Would. Start. With. WAY. Less. Motor.

You asked for advice, that would be mine. And I'm quite certain I'm not alone in my sentiments. 1/10 cars have seventy-three bucket-loads of adjustments and can usually be driven around a mistake on any couple dozen of them. 1/12 cars have comparatively few adjustments which means the devil is in the details--the difference between "on rails" and "a bag of ass" is usually a quarter turn of something away from each other. Take it from me--I'm the KING of turning "on rails" into "bag of ass". All adding horsepower to the mix does is make the difference an eighth of a turn or less away from each other.