The Groom: You can get some good ideas for suits on ebay but try to think about your budget do you want to hire or purchase. There's no harm in getting you ideas from the web.
Accessories - Flowers / Chair Covers
You can find real or artificial flowers anywhere nowadays do your research, if going for real I would speak to a florist first and touch and feel something in real life unless you know your flowers. Remember lily's may look and smell nice but they can stain your dress. Chair Covers - you can either hire them direct from a supplier either on ebay or not or you can use ebay to purchase your supplies and practice tying bows etc but get a family member to help out after all on the day you want to be concentrating on getting ready and not decorating the room. It would be a good idea to measure the chairs before purchasing any stock.
You can find some good deals when purchasing your stationary and it's always good to check out the ebay shops and asking the seller if they do samples - some won't as there's a lot of competition. If you've got a lot of invites and you have the time you maybe better of making them yourself, I did and I saved at least £150. I purchased the ivory hammered card of ebay along with the glitter butterflys etc and then there was a lovely wedding inserts cd for sale which had templates for how to address your invites. Just remember if printing on hammered card use a inkjet printer as the ink will stay on the card whereas the laser printers start to fade and rub off - I found out the hard way after printing 20 and only having 10 usable invites left. Practice with blank A4 to get the layout right and cut it to size such as A5 fold it, cut it, however you want your invites to be practice practice practice then the end result will be perfect! If your making your own table plans experiment with easy to do layouts as this will be one of the last things to be done approx 3 weeks before the big day and ask yourself do you want to be cutting out little bits of this and that making yourself uber stressed??