I grew cactus from seeds on several occasions from comercial packets and had great luck with the germination. The cactus grew VERY, VERY SLOWLY. I didn't have to transplant the little beggars for four years. So be patient.

That is my only advice.

coco

Of all the things I've lost, I miss my mind the most!!

I have grown cacti from seed..

I have a 'terarrium'  for starting cacti -I use a glass 'goldfish bowl'.

Place a few rocks in the bottom of the bowl, add a layer of spagnum peat moss ( soak in water first, then squeeze out excess before placing in bowl), use cacti potting soil or mix regular potting soil with sand ( about 40% soil & 60% sand) and add a layer of this in the bowl. Add your seeds. Cover the top or the bowl with plastic wrap and place in a sunny window or under a grow light. Once seedlings emerge, remove the plastic wrap. Keep warm and moist (but not wet).

I have used this method to sprout  Giant Suhauro, mixed cacti and recently a baby Aloe.

If you have trouble finding seeds, send me a pm and I can give you the web addy to a place I get my seeds from. 

Good luck!