Cut back blades are no such thing as a bodgey mod, and don't give more turbine flow at the expense of response.
A cut on the blades is used where there is not an EXACT spec that is wanted, ie one trim wheel is too small the next is too large, you then take the larger wheel and trim it so it has a total surface area somewhere in between the two.
The most important aspect of a turbo is the USE to which it is to be put, if around town all day long you don't want a T4 for example as they are shit low down and don't get real until around 4500, but they will produce big numbers at big rpm, if that is what you want fine then go for it.
As a general rule, go for the smallest you can get away with, as you will have less lag, and better response.
Do bear in mind though any future upgrades you may want to make and get one man enough for this.
A certain size turbo will flow a certain amount of air, BUT if the turbine wheel is too small it will not produce the goods due to the flow being lost, remembering that it is losing boost pressureall the time the engine consumes the air it is producing.
I went for a T34, on a T3 compressor housing, which is the same CORE as a T34, but std .48 turbine side.
It starts to produce usefull boost at 1800rpm, and comes in with a mighty kick at 3000rpm, it is not a sharp on/off like the T3 was but you can drive all day at normal speeds with less than 2000rpm in top gear, it will pull from around 800rpm in top gear without complaint as well.
Whatever one you get consider mods such as 360 bearing and step gap seals, these will cut down the oil consumption through the turbo by about 90%.
It is best to speak to people who have done your spec before about turbo choice as experience is a massive bonus.
A modded head can allow loads more boost loads earlier as well, usually de shrouding the inlet port area where the valve seat is.
tabetha