1st gen tundra with an eagle shell would be an awesome combination. the eagle fits really tight and clean in the 1st gen, my neighbor has that set up (eagle camper though). I had a hawk in my 02 AC for years (hawk is a little big looking to the truck) and it was a great combo, i did just upgrade my camper truck to a RAM2500, but i kept my 02 tundra and returned it to daily driver/shop truck duty and sold my shop truck 99 Tacoma. the 1st gen tundra IMHO is the best truck Toyota made to date.
for sure ride right air bags at a minimum (even though it is a shell, still will need them you will find) and since shocs probably need replacing anyway after 100K, i would look at bilsteen 5100 with rear add a leaf (slightly higher stance) which is what i did. but set my neighbor up with old man emu and add a leaf. if i did my own truck over, id go old man emu