Should we register a subsidiary company in England?

I'm a US resident, and a few months ago a friend from back in the UK pitched me an idea for a SaaS product for the market sector he works in. We've built the product, and we plan to incorporate and launch this summer. Initially, we'll be targeting companies in the UK, as he has pre-existing relationships with many of them.

All being well, as we grow we'd hire developers here in the US, as they would be working under my direction. Initial sales and support would be hired in the UK, under his direction, to better serve UK customers.

Would it make sense to incorporate in the US and have a wholly-owned subsidiary in the UK? On the one hand it seems like it would be simpler; on the other, more complex. I haven't talked to an accountant about this yet, so this is just an initial exploration.

If we did that, how does money flow from the one making the sales to the parent that has staff to pay?

(One other point to consider is that in the long term, my co-founder would like to delegate the UK work and transfer to the US. Would such an arrangement make sense when considering an L1 (intra-company transfer) visa?)