The ofna was a copy (and some say better) of the nitro TC3...they are a decent car and would be good for bashing as it is shaft drive esp at that price.
The one thing you want to ask your LHS is if they love them enough to stock parts, esp since it looks like thay are clearancing them out.
With that being said, why buy another brand that you have to mainating a different inventory of parts for?...with over a 100 cars, I learned that lesson in spades. If you are looking for something different, buy another rs4 and set it up as a vintage bodied musclecar with those vintage tires. This way all you parts match, you always have spares, yet you have a completely different style of car.
BTW, I think the HPi engine is way better than that force 12....
www.fastharry.com---search "fastharry" on facebook
See Fastharry in Super Nitro racing at the HPI CHALLENGE...