I'm extremely happy with my Neuvation m28x's. Wait for the R28's to go on sale as the "deal of the day" and get them while they're cheap if you're looking for bang-for-the-buck. I got a full bike (fc100) from him and purposefully got the m series wheels as heavier training wheels with hopes of getting lighter race wheels in the future.

If the intended purpose is for training and you plan on buying a new set later, the weight of the wheels won't matter much. In that event, try to find the "highest quality" for your money. (I'm convinced the Neuvations are quite high up on the quality per dollar scale after riding mine and seeing the wheels on some others' bikes). If the intended purpose is for all-around-use, go for the lighter ones. I wouldn't recommend tubulars for training though, as that could be very expensive depending on the quality of the roads in your area.