Looking to buy some DVR's

Hello, I am from Uruguay so first of all sorry for my english.

I have a Security camera setup of about 40 CCTV cameras. They are connected to 5 low quality LongSe DVR's.

I am recording on a server with a CMS software all 5 DVR's at once. The problem is, that program crashes, it is hard to use and the overall quality of the setup is bad.

I am looking for 5 DVR 8 channels and a CMS Software for Windows in witch I can connect and record all 5 DVR's at once with an user friendly interface and stable software.

Becouse I am recording on a separate server, those DVR must not include a hard drive.

I need some information on what I need to buy and a price.

In case I want to buy it, the package should be sended to Miami, I have a courier there.

Thanks,