Wah............your ILs sound like mine.......
Food wise, you can go searching for caterers. But be prepared to have to pay for the food tasting since they might be quite fussy lor. I paid 4 other caterers for food tasting before settling on this caterer.
Anyway, alot of caterers are having their free food tasting soon, so sign up and invite your ILs to go with you
If FH not helping, go direct to them and tell them you value their opinion, so want them to go with you to see the deco and taste e food

They will be more than happy.
Select catering is having theirs on 8th april.
www.select.com.sg got more details and registration
If you decide on them then let me know, I tell my coordinator

She will help you do nice nice
Actually, how i settle my ILs was: we can onli afford ___tables. My family needs ___tables, our friends need ___tables. The rest is up to you to decide. Just like that. No arguments, no nonsense to deal with

If you want more tables, then you fork out the balance.
I have alot of frens, that's why I have the lunch reception for my friends (quite wild party planned

). Then dinner is for relatives onli.
Another way is you just tell your ILs that not having dinner. Then your parents seperately invite your relatives for dinner. tt was what one of my couz did. Cos his wife's dad is big businessman, if have dinner need to invite almost 60 tables for their side onli. and my couz just started work onli, also cant afford so many tables so he just said no dinner. Then my aunt also paiseh tt her onli son marry, no dinner, so they planned a small dinner at restaurant for the family onli. at Tunglok, ard 10 tables onli lor. Simple and easy on the pocket. Plus everyone was happy.
Then his wife's dad also held his own dinner for his relatives and frens, then her dad also v understanding, surpluses from AP give them to go honeymoone (they went europe tour 1 month lor!!!)...