Hi,
welcome to Bangkok.
Here are a few addresses in the Sukhumvit Area located at a walking distance from Nana Plaza:
Grace Hotel
Sukhumvit Soi 3
http://www.gracehotel.th.com/
Dynasty Inn
Sukhumvit Soi 4
http://www.dynastyinn.com/beta_DynastyInnBangkok.htm
Nana Hotel
Sukhumvit Soi 4
http://www.nanahotel.co.th/html/index.html
Woraburi Inn
Sukhumvit Soi 4
http://www.woraburi.com/new/woraburi...aburi_inn.html
Sukhumvit Crown Hotel
7 Sukhumvit Soi 6
http://geocities.com/sukhumvitcrown/
Ruamchitt Plaza
199 Sukhumvit Road (Near Soi 15),
http://www.asiatravel.com/ruamchitt/index.html
Regards,
Bobby