Newbie looking for online equivalent to "OPMS Silver Malay"

I'm new to Kratom, having been given a few samples from a coworker which I really enjoyed. We work 12-hour overnight shifts, and twice now kratom has really helped as a nice alternative to caffeine to stay awake and stay productive. The kratom I tried was called OPMS Silver Malay Special Reserve, and it came in 500mg pills. Taking 4 of these was enough to make a huge difference. I'd like to get something equivalent online, in powder form, since it would hopefully be less expensive. The local headshop charges 39.99 for 30 grams (60 pills) of this kratom.

So, what could I order online which would be the same type of kratom? The stuff I took had a slightly stimulating quality to it, just right for a long, boring 12 hour shift in the factory I work at. I'm assuming the kratom I tried is just powdered kratom placed into capsules and not some type of extract, but I don't know that for sure. When I look at prices online for loose powdered kratom it appears to be about 12.99 or less (depending on the quantity one orders) for the same amount of kratom. Assuming it's the same quality, that seems to be the way to go.

Again, because of its intended use, I'd like to find something equivalent to the "OPMS Silver Malay" since its slightly stimulating properties seem to be perfect for my intended use as a healthy supplement to aid in my work productivity, seeing as working the overnight shift is such a challenge.

Thanks.