Well, you're not really sacrificing anything.
Charisma is an attack stat for paladins, so you're still hitting just as hard as others.
You get plate armor proficiency and heavy shields as a class feature, so you don't need Str/Con to qualify for those.
Hospitaler in itself is a ridiculously overpowered paragon path. No need for special tricks other than having high Wis/Cha.
There's a feat in PHB2 that allows half-elves to treat their dilettante power as a new at-will. I took Astral Seal for the surgeless healing at range.
The daily utility at 12th level is stupid powerful. Heal an ally 1d6 times your Wis modifier every time you hit for the rest of the encounter? Ummm...yeah.
Wrath of the Gods (paladin daily utility 6) is also amazing if you want to ramp up the damage factor, turning you (and everyone else adjacent to you when you cast it) into strikers for the rest of the encounter.
I just basically took several charisma attack powers that either affected a large number of people (Astral Thunder, enc 7), or allowed a healing ability as part of the power (glorious charge, etc).
Oh, I also took the life domain feat to grant an ally temp HPs every time I used the bolstering strike at-will. Basically, between the temps and the surgeless healing I'm throwing around, my party tends to not use any healing surges.
A few items like a healer's brooch or mace of healing is also useful to increase the sheer amount of healing you put out.
If you have the spare coin, a preservation shield is a useful item to have (daily power is to grant temp hit points to your allies equal to the amount of healing surges you have). I've got a couple.
Oh, and I took the Bardic MC feat, just to have another healing ability since it's charisma based (plus it gives you the ability to use wands and gain access to neat powers like ethereal stride).