As you'll need near field monitors anyway, just buy one decent near field and then you're half way to mixing in the future. You'll have to accept that the sound will change depending on your room position but that (to an extent) will be the case with ANY amplification system because what you hear is a combination of the direct sound and the reflected sound....
Yeah, I guess I should stop moving around the room when playing
On this last point, pop over to the Sound on Sound forums and look at all the info on home-made sound treatment. Basically, 4 inch acoustic grade Rockwool plus some wood and cloth will cheer up ANY speakers you end up getting for very little money and ensure you can crank it a bit louder without the room taking off
Well, that would be much more complicated. The place where I play is also the play where I work: about 8x4m, with 2 desks, countless computers, etc
Out of curiosity: is anyone using only one monitor with the kemper?
BTW I've seen the price of the Tannoy 502A. Not many distributors in Italy apparently, but the price for a pair would be more or less in the initial budget.