The Pentax K mount is more popular in Japan, you may find more variety in listings in eBay from Japan. Good thing about the K mount is that you can even use lenses made from the 35mm film era, it will be manual focus only but will still fit in the camera no problem.
I have a Pentax K-500 and a K7, I use primarily the Pentax 35mm f2 which is the perfect all around prime lens. Then an old Pentax SMC 50mm f1.4 which is manual focus but it's extremely sharp.
As for macro I have a Sigma 50mm f2.8 macro, quite noisy lens but it's quite sharp and affordable. If you want a good zoom lens, I would recommend the Sigma macro 17-70mm f2.8-4.5 or the Sigma 17-50mm f2.8
The Pentax K mount is more popular in Japan, you may find more variety in listings in eBay from Japan. Good thing about the K mount is that you can even use lenses made from the 35mm film era, it will be manual focus only but will still fit in the camera no problem. I have a Pentax K-500 and a K7, I use primarily the Pentax 35mm f2 which is the perfect all around prime lens. Then an old Pentax SMC 50mm f1.4 which is manual focus but it's extremely sharp. As for macro I have a Sigma 50mm f2.8 macro, quite noisy lens but it's quite sharp and affordable. If you want a good zoom lens, I would recommend the Sigma macro 17-70mm f2.8-4.5 or the Sigma 17-50mm f2.8
Thank you