Who has grown some of these cultivars? Where have they thrived? Which would you recommend?

I grow 4 Topguns cultivars adding one a year over the last 4 years. The oldest, Power Broker blooms but last season, all blooms were singles. Blooming Machine looks good but gives me only a third of registered bloom count and 2/3 of registered height. Lola Scott is very late here. Looks good but a very low bud count. Lastly, White Knight added last year so too early to tell.
I guess I have never looked at this collection like this before but, now, I would say they are not good selections for my short season in my climate. They don't die but don't thrive either, slow to grow a clump. I am a colder zone, probably a 4 by US standards. They would likely do well in your space, any of the ones above. They are all pretty blooms.

Good information, Raven

Bob hybridizes in Oklahoma City, Zone 7. I grew a couple of his with no problems about 25 miles south of him. When we moved his hems to New Mexico in zone 4, they suffered and then disappeared.

Charley

I grew Topgun's Molten Lava for several years before a friend of mine asked if she could have it. I got it from Bonnie Nichols who grows daylilies about 150 miles south of me. So I would say at least that one does fine in this range. I'm not a huge doubles fan, but I was impressed enough that still check out Topgun's site to see what the Scotts are up to every now and then.

I've grown several for the past 10 years and had good luck with them. I currently have 3, springfield mo

I have only grown one and it did not do well here in my garden: 'Topguns Pinwheel'