Timewarden's would probably be one of your better bets, just cram it full of stam gems with a decent leg path as mentioned above.
Also look at enchants (as mentioned above), +150hps to chest (looks un-enchanted) would be a bonus and fairly simple, regemming gloves would also be a fairly cheap upgrade. If you need Hps and Def you could always bung in the def/stam gem in the gun. Which i've done, and seen a couple of people do when juggling gear around, especially if/when you start picking up badge items.
A cheap shield is the Ogrila rep one and is much better than what you have. I had the same and farmed ogrila rep/dailys to pick it up, and used the cash to fund gems and enchants. I've just replaced it with the shatar one, as I regemmed it with str gems for hahadps, with NB being nice.
Gemming wisely and ensuring everything you have has some beneficial enchant will easily give you several hundred more hps. I find executioner giving more threat over mongoose, but until you beef up a bit the latter may be better, or even crusader if cash will be an issue just for some grunt. The basic kit seems fine, couple of better items than what I started with, just needs 'enhanced' to something near it's potential. Then expect it to have a short shelf life until you get the drops you want.
Former TBC/LK Tank
Waiting for Dunmail Jnr to sleep to enable online gaming.