Very nice choice.
After doing extenisive homework myself, I'm finding that the Humber Destroyer is very good value especially if you don't get it in safety orange (resale value). It's not a Gucci boat but Humber gets the important bits right. Your family should be safe & comfortable in that boat and it's solid; you'll have many years of fun it. Another hull I found equally as nice is the XS Ribs.
Only offering a warning about stripping your Brig if it's decent good working shape, I'm sure willk was thinking the same thing when asking his question above. Your going to have more problems selling a stripped hull and for much less money as opposed to selling it complete. Stripped ribs are usually reserved for fire sales.
You may want to do a cost differential between selling a stripped boat to a good complete boat. You'll be surprised how much good gear you can get off eBay and gumtree in excellent to new condition (sitting on shelf) for little money; that's if your short on funds for new dealer gear for your Humber. You now have 8+ weeks to shop around for gear. I would not be surprised if you'll save more money and time that way compared to stripping the Brig. Trying to use gear from another boat can be quite problematic and time consuming during the install process and often it's expensive to getting it all to work properly.
However I can totally understand about using the same motor if it's a good Honda four stroke. Maybe find a good working 2 stroke for the Brig in order to sell it complete.