Hi there-
I'm in full LBA mode

Need some help with identifying lenses that are 200mm or greater.
I don't intend to use it for birding but for capturing indoor concerts, and possibly outdoor night concerts.
I currently have a Pentax A 70-210, which is constant f4. However, based on the results I've gotten I'm wishing for a longer reach or faster (larger min aperture, 2.8 or less). Wish my Cosina 55 1.2 had a longer reach.
I was eyeing the Pentax 55-300mm as I've seen good reports of it on here but I'm concerned that it's f5.8 @ 300mm might not be enough for indoor or nighttime outdoor shots.
Using the price of the Pentax 55-300mm (~ $350) as a guideline, I'm looking for what my options are.
I've seen the Pentax K 300mm f4 - how does this compare to the 55-300?
I may also be able to get a Pentax k 400mm f5.6 but I'm concerned about the f5.6 limiting me with low light.
I've also seen the Pentax 200mm f2.5, however I'm not sure I can afford it and I might wish for more reach
The Pentax DA 200mm 2.8 is definitely out of my reach, being ~$800
Any other lenses out there that you folks could recommend that I could look into? Oh, BTW, this will be paired with a k200d, and I've also got a Pentax LX