somewhere on the website I think they have a takeaway guide - password is cycling, why don't you have a mooch?
I was told a mixed vegetable curry was 10 syns, so you could have that and boiled (is pilau same thing but coloured?)rice - watch out for rice with "bits" in like vegetable rice, I thought I was being dead good when I ordered that but it came greasy - I think they must fry the vegetables into it like egg fried rice!
It might be hard for you to avoid the poppadums for starters, so syn them, but its reasonably easy to only take half of one and nobody notice to moan because you're being boring and dieting! The chopped onion/veg thingy is presumably free, and try the yoghurt based stuff to be relatively low syn dips-wise.
Dry cooked chicken dishes are the healthiest, and if you had one of those with pilau rice that would probably be your best bet, using the chicken as your HEb.
Alternatively I think most places do English food as well, so maybe look and see if they have an omlette you could ask for a salad with instead of chips?
If the worst comes to the worst I'd do a one off and forget SW unlimited portions, and try not to eat everything, only until I was satisfied, therefore minimising any damage, and make sure you're not starving before you go.
Hope you get on ok.