I'm pretty sure that the Avon is a medium V hull, which will mean that it planes easily and is more economical than a true offshore hull at the expense of some comfort in the rough. Probably not a bad choice for the uses you have mentioned, but bear it in mind when you are on more adventurous trips!
The Honda 130 is a heavy engine, and wouldn't be my first choice for this boat. Here are some weight comparisons to look at (they are for 115's, but it gives you some idea)
Yam 115 2-stroke - 163kg
Evinrude 115 Ficht - 170kg
Yam 115 4-stroke - 181kg
Honda 115 4-stroke - 225kg (the 130 is the same weight btw)
Have you sea trialed the boat with your choice of engine? If you have and you are happy with it then go ahead, if not then make sure it
is the right choice.
Is your seating from the standard Avon range? ie the wide console with front seat and 2 x 2 person jockey seats? If so, the jockey seats only have one backrest, so make sure you will be comfortable using them for any length of time with two people on them and solo.
It looks like Avon use standard seats and consoles from Outhill, so there may be other options available, depending on who is fitting out your boat.
What is the capacity of the fuel tank? Make sure it's big enough to easily get you across the Channel as refuelling at sea from jerry cans is a real pain!
Just as you thought you had made all your decisions . . .
John