No particular supplier in mind, but try to find one who is willing to supply on a consignment basis (I think I went to bottles and bottles, but I think most of them will do this). For example you buy say 50 bottles but any unconsumed bottles, subject to a min of say 20 bottles "consumed" can be returned for a refund. reason being that you have to order a bit more unless you want to run out in the middle of the dinner which is a bit paiseh. How many bottles will also depend on the type of guests you expect. And of course, because you're at that stage in life, you are balancing paying for the wedding, paying for house, etc, there will be quite a bit of financial burden unless you're minted or the parents are helping a lot, so try not to overdo the cost.
My own view is that unless you're minted and can have a sommelier offering a full range of different wines, don't aim to impress with the wine. Be happy with people enjoying the food with the wine and company. They may not go "oh that 1975 Petrus is brilliant" but as long as it's not terrible, it's ok. Then it's more the company (and the couple) that they'd remember.
For wedding wines, try not to choose anything on the extreme of the taste palates because there's a higher likelihood that people will hate it - I would go for a middle ground "safe" type. When I was at the marrying age, I didn't know much about wines so below are just some thoughts to get you started - perhaps the other guys with more knowledge on wines can provide more information / suggestions.
For whites, wines from Marlborough (NZ) are generally quite well received so it's probably a safe bet because they tend to be quite bright and fruity. the Matua Sauv Blanc is currently $27 on redmart although you will probably be able to find a supplier who can give you for less if you're ordering in bulk. There might be other cheaper vineyards as well. I don't do much whites so perhaps the others might be able to give other suggestions.
For reds, I would suggest you avoid both the pinots and the shiraz because they are on the 2 ends of the scale (Pinots being light bodied and shiraz being full bodied) so it's usually love or hate (and there will always be people from both camps at the wedding). Go for something like a Cab Sauv or a Merlot which is usually more acceptable to the general palate.
Or perhaps explore the Spanish Riojas - I don't know what pricing is like in Singapore, but I've had many in Spain because you get a bottle (or at least a carafe) at every meal and it will cost between Eur5-15 (if you splurge) at the restaurant and it's perfectly decent wine on the cheap - it's about the same price as bottled water. While prices in Singapore will be higher, I think it'll probably still be in the cheaper range.
