Dark Silver set for high resistance
Bramd for high damage output and general good times
mace for a heavy offhand
dagger for parrying offhand
Rings as required for supporting the tankness
Less stats required to level than in other souls games for a true tank build, although, it's probably a smart move to go claymore/bastard sword early game for high damage, but two hand until you've beaten the phalanx.
For an alternative, change the dark silver to fluted set, then lower the endurance to 63 to then be able to have a few more points in vitality if you'd prefer that.
Shield bashing not included in this build despite it being a tank, shield bashing is nowhere near as fun in demon's souls, and you'll have an all round better time hammering away with bramd than anything else, although, if you prefer the claymore, you can lower your endurance even more, then add some dex for the quality scaling, this build is highly adaptable, because all soft caps have been broken on the 3 stats that have been levelled, so you can just remove armour and endurance points (maintaining mid roll - <50% equip load) to then be able to do access buffs, spells, and the like to whatever you fancy.