Your long term plans for the car should be factored in too - you've been an owner for a long long time but I'm not aware of whether this is your first supra or you've had a few during your years of ownership. If you've had a few and chances are that you'll change again, maybe a big investment like a full respray isn't wise as you'll never see the money back. On the other hand if it's a keeper and it only has the cosmetic issues in your first post then the respray would be a good investment.
Fresh silver paint with facelift lights is lovely. If you're considering a colour change I'd stick with a Toyota colour, and personally would also lean towards one of the rarer colours (msb, djg, gunmetal or 6no)