I'm sure HSI stocks some bun parts but if you're going for reliability and product support I would choose xscream if you want to go the 1200 route. It's a tried and trued setup with tons of info on how to set it up from multiple people. With the Bun, you're limited to HSI for support. Not saying that's a bad thing, but just a thought. Bun engines are just starting to be a more common thing in the US. It's been proven they rip extremely well though. There's motors I avoid due to lack of support.
Tpe1105 would be an upgrade over your dasa1100 especially if you choose their higher end porting. Plus
@Jr.(he also would have great advice on choosing a 11-1200 motor and engine reliability)supports their products and would make sure you're set up extra well.
If youre chasing reliability and going full out with high compression, I wouldn't recommend a 12 unless you're willing to tear it down preventively and you understand the risks.