Have a look also at the Bulldog, they've become reasonably inexpensive and are well supported from within the UK community. It's a gorgeous aeroplane to fly, with fairly reasonable legs and quite a comfortable cockpit.
A friend who has a T67 seems to have significant issues with regular service bulletins and very slow supply of parts, but loves the aeroplane when he's flying it. Statistically the small engined aeroplanes do not have a good safety record, but the military spec (M200 and M260) variants are very good in civil use.
I haven't dealt with the G115 but have dealt with other Grob aircraft in the past. Their product support was always excellent.
All I really know about the Zlin is how ugly it is!
G