J-red is 49cc, but has plastic crankcase which I don't think holds up over the long haul. I'd pay the extra $$$ for the 2152 and magnesium case. If you believe you may be in a different situation in 3 or 4 years and not need the saw so much, 2150 is OK bet, but at 10 cords/year any 50cc saw is a little light. 50cc's will do the job, but have to work pretty hard...it's a lot more comfortable with the next size up...
290 is kinda heavy for 50cc saw and is Stihl's consumer-grade saw. Basic chassis same as 390, update of 029/039 saws. I will say that my BIL's 039 keeps coming back for more abuse, so they must hold up well, even if they aren't a top-level performer.
I have no experience with 455, except what folks here say. I imagine Husqvarna would refuse to market a true dog that didn't hold up in testing. I know a pulper that used to use Husky 55's, which was also eventually considered a consumer saw; if the 455 intended to replace it they'd have to engineer at least some of the 55's steady dependability in.
Actually, if I was in the market for a new saw in that size range, I'd call around...there may be a few regular old 55's at a good price somewhere near you. It hasn't been a year yet since they dropped from the catalog....