Are you referring to torrents or DVDs? If DVDs- I can only reccomend you to eBay.com or amazon.com. If Torrents- www.boxtorrents.com,www.datorrents.com or if you're not happy with results www.google.com is the best =) Streaming Websites- <not reccomended since most anime streaming websites do not upload old licensed anime>
I havent tested this myself... but these seem to be streaming episodes of the series =p http://vodpod.com/search/browse?q=gundam+wing