Hello I have recently made several artificial troughs and was wondering which small alpine plants can grow and thrive in them under the hot zone 8 Texan sun

Good question--
Sorry, I don't have a good answer...but, if you find any, please let me know!
For the record, I have fried a lot of alpine plants in the summer here in Utah...
(ugh, 106 today when I left work)

Of course there are plenty of different cacti that will do well. And there are several Phemeranthus species native to Texas. Probably, P. calycinus will be the only one you'll be able to find. Viola pedata is worth a try, along with the thicker (usually bluer) foliage penstemons, like Penstemon grandiflorus. Maybe look at the smaller salvia species. Take a look at some of the offerings here:
https://www.highcountrygardens...

What plant have u had success with over in utah

Well Josh, I've been thinking on it...
if you'd asked me a few months ago I'd have had a better attitude about what 'grows and thrives' in the sun here...but I just recently wrecked a bunch of stuff with epic irrigation fail, accidentally of course

short list of what grows and thrives without water
Convolvulus arvensis
anyway
the one advantage I have here is winter; the true alpines appreciate that it seems

Like Rick said, Phemeranthus, penstemon, and salvia all do very well for me in full sun, and there are some really cute small penstemon and salvia

for example

Eriogonum should do well for you, and there are several little ones suitable for toughs


Dianthus rocks in the sun!
some of them can grow into fairly large hummocks over time, but I really like the tight little cushions even when they're not in bloom

Dianthus subacaulis ssp. brachyanthus
many to choose from

hmmmm,
Armeria
Erodium
Erigeron
Hymenoxys

Oh, and Daphne! There are lots of super-cute little rock daphnes to try
4th of July, sunset pic of one of my favorite littlest --about 4 yrs growth

sleeping cat for size

I feel for you, dirt. We've also had the epic irrigation fail and lost so many plants. We felt like giving up, but slowly we managed to get things back to looking good. Our lousy water plugs of the dripper emitters, so we have to check them constantly to make sure they're still running.
I just starred this post, so I can get some of the plants you showed. Lovely photos!

@Overgrown_suncity Just curious if you ever selected anything? I've just torn out an old playground, brought in a bunch of rocks and am trying to find some good matches with a bunch of cacti I've put in