Pentax K10, Lense Choices....Banging My Head

[mommato8]

I have a Pentax K10 & my trusty old Asahi Pentax K1000.For my K1000 I mainly use a lense that is marked SMC Pentax-A 70-210mm,1:4. Sometimes I switch to my 50mm , 1:1.4. The only lense that I have specifically for the digital [K10] is Pentax-DA 1:3.5-5.6, 18-55mm AL [kit].
I've had this camera for approx. 6 months.So,why do I only have one lense for the K10? Because every time I try to figure out what lense is good quality,I feel like I'm banging my head against the wall. I have read every thing that I could find around the internet.But,I'm still not sure what to trust.
Can someone please help?I don't want to buy a piece of junk.I would like to stear clear of slower lenses,when possible.
Are there certain brands to avoid? Are all Pentax lenses decent?I have seen a lot of talk about Sigma.It seems like Sigma & Pentax may be the better choices for my camera.
I would like to find a lense for the K10 that would work as good as the 70-210mm does on my K1000.Any suggestions?

I am also considering some trips to the mountains to possibly do some shots of wildlife.I have a dear friend who keeps begging me to come.I would like to find a decent lense for shooting wildlife.I know that I can switch my old lenses from my K1000 to the K10.But,the 70-210mm is my biggest lense.I think I would need at least the range of 300-400mm for wildlife.Plus,I really would like to keep my old 70-210mm on my K1000.So,as far as a lense for wildlife,would it be best to look at only Pentax or Sigma?Or are there another brands that are good? Any suggestions on a lense or lense & converter combo?

I also do a lot of people shots.Mainly,pictures of children being theirselves.Sometimes,group shots.So,I guess I could use some suggestions on that.

Again,I know that I can use the older lenses.I'm always on the look out for old lenses for my K1000.But,I am interested in find a few new ones just for use on my K10.I had a hard time convincing myself to even start shooting digital.Now,I'm so frustrated trying to find decent lenses.

Cathy

 

[Steph]

What is your budget for the lens(es)? There are many different options at very different prices and it is hard to make suggestions without knowing how much you want to spend.

If you want a high quality lens for your K10D that as the same range of fields of view as your 70-210mm on your K1000, have a look at the Pentax 50-135mm f2.8 DA* ED SDM lens. It's a fast constant aperture lens, which looks very good.

 

[mommato8]

Thank you for responding.
I know there is quite a range in price.That's part of what concerns me.Some brands seem to low.I can't spend $2000 a lense.I am in the market to get more than one lense. I would like to spend as little as possible for each one.But,I don't want to spend so little that I end up with junk.
Cathy