What sort of tip shapes are you thinking of? I'm suspecting they will be more similar to metal engraving tools, rather than wood carving chisels.
In which case you want a flat surface to hone them on - hence a wheel giving a hollow ground isn't what you want.
The pro's use rotary laps (think: the side of a wheel), of diamond in differing grits. Effective, but expensive for getting started. 'power hone' is a particular brand.
For hand use, I'd go with diamond plates. With a small contact area, carbide blanks will tend to wear grooves in stones; and the sustaining flatness of diamond plates works for you here. Even cheap plates are likely to last as long as the blanks will. I've rough shaped some carbide on a basic SiC wheel on a grinder, which might speed the process up a bit. It's very nearly the same hardness (give or take) as aluminium oxide; so SiC, diamond and CBN are the order of the day.
In terms of blanks, here's a couple at £13 a pop:
http://www.ebay.co.uk/itm/1-tungsten-ca ... 0821807776 and
http://www.ebay.co.uk/itm/1-tungsten-ca ... 1587302917
Are you sure that HSS won't do? You can get a a couple of bits for £3 (albeit with a long arrival time):
http://www.ebay.co.uk/itm/2-Pieces-3mm- ... 1433259215 and no doubt more locally too.
If you're thinking of making your own tools, it might be worth getting some anyway, so that you can experiment with tool geometry (and sharpening process), even if they wear too fast to be effective for extended use.
