Fensport.co.uk sell the motec M4 for £1169 inc. vat
It's not 'that' expesnive.
As for chaning size of injectors RDS. That all depends on what fuel pressure your changing too, and what injectors you were running in the original map. It's not exactly hard to work those figure's out. I have the DTA software, but will have a monkey around with it. It's hard to believe it can't do something as simple as that. Emerald can even modify it's maps accordingly!
I notice now you've put PROPERLY in there, as though anything I now say you'll come back with, 'does it do it properly though' lmao
It's just a tiny bit of maths. If I changed from something like 700cc to 1000cc, I'd be in after a while to get it on the RR again for a quick tweeking on the fueling maps...