Thombat, if you're going to stay within the 290/310/390 family, I'd suggest getting the most powerful saw on that chassis (the 390) if you can afford it. If my memory serves me, the 390 is justifiably more powerful, and the weight isn't a huge deal...
However, if I had it to do over again, for the money I'd actually go smaller... Probably along the lines of a 260pro or 280wb. More money for a smaller saw I know, but you save weight, and the technology is far better than the aging 290-line. If I were the dealer, I'd have probably given the same advice... Better chance of selling a $450 saw than a $600 saw anyway. Not to take away from the 290's, but with others available, if you're serious and enjoy wood cutting, I think you'd be happier with the smaller, more nimble 260 or 280...