Trading help with internet business

[nikon]

Please help I am a sole trader have an internet website and sell on e bay but need advice on generating more sales. Have problems getting stock from America cant buy anywhere else for some items and feel I am letting customers down as I cant always supply goods. I pay for goods in America up front and then there is problems with delivery. So sometimes I cant track whats been delivered and whats been paid for. Its the American end thats the problem. Do I close my website down while I redo it and potentially lose customers or keep it running and diissapoint customers while they wait for stock. I feel at the mercy of distributors in America. I need more finances to but up front stock at lower cheaper rates and then it would be easier finding it difficult to get a backer the banks wont help as they feel I am a credit risk. I dont have a problem selling the stuff its getting it.

Any ideas???