Well others will be better informed than me. But I have had 25 holidays on the Norfolk broads, and I have a fly bridge cruiser, unfortunatley the two never met! All the hire craft are made especialy low to go under the bridges. Yarmouth would be the first hurdle IMHO. Course it dependes on the tide and the boat in question. Short answer is though, sorry yer not going very far!!
There are plenty of large cruiser's on the Southern section as Broom build them at Brundal but this may not be a large enough cruising area.It's the bridges through Yarmouth near the Yacht Station that would appear low and do not open!
You can pass through Lowestoft (Mutford lock) and into the broads with no problems except swing bridge delays. Then there are some railway bridges which will open for you on signal (give 'em a toot).
The main problem is the bridges to the northern section (Wroxham, Horning etc)
at Great Yarmouth. You must get there at dead low water, and with an air draft of around 12ft 6ins you can usually get through. There are height boards at the bridges and combined with the tide tables you can generally predict the best time.
The folks at Yarmouth Yacht Station are helpful and worth a call. I have been through on a Sealine 310 flybridge but had to take the small anchor light mast down.
The same low water approach applies to the Haven Bridge at Great Yarmouth.
On the Northern Rivers at Yarmouth you would have to check the low tide heights and make sure you time it so that you can get back out.
I can struggle at Yarmouth end with 10'9 airdraft and have taken off the radar to get through.
Forget the river Ant the bridge at Ludham is too low.