Dear Mr.... We are really interested in the equipment manufactured by you. Please, send us a detailed offer so that we will be able to plan our investment. Our research showed that working with your equipment would be beneficial for us.
Remarks about the translation
manufactured by you = manufactured by your company
"The equipment manufactured by you represents a serious interest for us."
That would be natural in English as:
"We are really interested in the equipment manufactured by you (your company)."
and "Please send us a detailed offer so that we'll be able to plan our investment."