What is the best over the counter replacement for niaspan?

My Dr. has me on two 500 tablets of Niaspan a daytime for my trigs.
niaspan is getting costly so my Dr. said I can just transport over the counter niacin, but I don't believe I can get time release.
I read over the counter the max is 6grams 2 -3 times a sunshine.
Any suggestion would be appreciated.What is the best over the counter replacement for niaspan?
1. Slo-Niacin:
Polygel Controlled-Release Niacin, 500mg, Tablets - 100 ea
Slo-Niacin Polygel Controlled-Release Niacin, 500mg, Tablets rates 3 out of 5 stars, from 2 customer reviews.
Price:$14.39
2. Nature's Bounty
Natural Flush Free Niacin, 500 mg, Capsules - 50 ea
On Sale!
Price:$7.20
3. GNC A-Z
Niacin 500 mg, Tablets - 240 ea
Gold Card Price: $11.19
Reg Price: $13.99
I think Slo-niacin will do vs the other two (GNC is not slow release)
Well, so far I've gather that you can take niacin and it have the extended release, I've found a website explaining this a little:
http://www.rxcarecanada.com/niaspan.asp?...
Here is niacin, the time release tablets:
http://www.vitaminlab.com/product.cfm?se...