High temperature heat pumps, any experience?

We are looking at an older property and ideally we will replace the old oil boiler with a heatpump (air to water) I have seen a couple of the high heat output pumps but wonder if they are any good.

We will also be installing a solar roof system with an aim to reduce the houses foot print as much as possible. The house will need a re-plumb and rewire so we figure that we had better do all the core work while we have boards lifted. Ideally a new highpressure system and zoned heating.

The house we are looking at is 3 stories, 2 over basement (half underground) and we want to make it as comfortable as possible with as small as possible running costs. House is c 1870. Down the road we would like to install original (cast iron) rads that would suit the property. We would also like to install a stove, if possible with back boiler so when we do light the fire it can assist to heat rads / water.

We will endeavor to bring the house back to its original state with the modern tech there but not highly visible.

Anyone in the know that could throw some ball park figures at the items listed below?

House is 2500 sq ft.

1. Replumb to include larger hotwater tank and high pressure system.
2. high heat output air to water heat pump.

We will also in time replace all the crappy aluminum windows to timber sash (cost is a factor here) and will take full advantage of seai grants available.

I will do a lot of the dog work myself in the property when it comes to the rewire (i.e. pulling cables and lifting boards, chasing walls etc) to keep the cost down. I will also be running a full data network to facilitate future modernization.

Any thoughts appreciated