New heating system

Im renovating a house for me and my family to live in. It's a 4 bed semi including a loft conversion which contains a bedroom and study.
I'm putting in wet under floor heating myself on ground floor.
The quotes I'm getting are for a new 40kw Baxi boiler, with new gas supply pipe on an easy 5m run from the meter.
Upstairs it's 3 bedrooms and landing, so 4 double radiators. En suite and bathroom fitting of a two towel rails I provide. Loft conversion is 3 double radiators. It'll be be copper piping throughout.
I also want new hot and cold pipe work put in for water.

Quote 1: local firm. £5200 with a Baxi boiler and cheap rads bundle.
Quote 2: local lad works for himself . £4500 with boiler. £3500 if I source it. Thks will be middle of the road rads, not the cheapest ones.
Quote 3: pending.

Any thoughts are welcome.
Area is north east.