Dear Sir/ Madam,
I am willing to help you with the project described. It sounds really simple from the description below, so I assume no special skills are required.
I am currently unemployed, so at some point I might be willing to take more than 20 hours/week and also I am available for a long-term commitment.
Although I am from Bulgaria, my English skills are proficient, so no language barrier is to be anticipated.
Should you need additional information, I remain at your disposal.
Best regards,
Zoya