Where to buy Relevant Solo Ads?

Hello all, I am new to email marketing and I have a question that you wise folks would very likely be able to answer.

Short question: where can I find solo ads suitable for "website services" niche.

In my search to find suitable Solo Ad vendors I have realised that the "Internet marketing" niche utterly dominates the field, and that because of this I am finding it hard to find suitable vendors (please bare in mind that I am new to this, and so might simply be making newbie mistakes).

I have recently join Udimi (Solo Ads) and I am experimenting with their vendors - I cannot yet conclude if Udimi does not work for me as I have not yet purchased enough slots, nor am I 100% that my funnel is sound.

I would like to ask if anybody can tell me how to find suitable vendors, (assuming solo ads is the way to go).

Any advice would be greatly appreciated!

Thanks!

FYI:
My website is: www.forgesite.com
My landing page is: www.forgesite.com/your-website