I want an inexpensive 22LR target pistol and seem to lean towards these.  How are they and what barrel length do you recommend I should start out with?

I found the Neos to have the most uncomfortable grip angle.  The gun did not point naturally when I got a chance to test fire one.  Make sure you hold one first before you buy.  

Neos aren't flying off the dealer's shelves. I would suggest the Browning Buckmark for what you want.

My .o2

The grip isn't for everyone, the safety is awkward but it is a tack driver and 100% reliable, unlike my mkII that jams after 50-70 rounds. The mkII is also a PITA to field strip. The Neos is extremely easy to field strip. No tools required.
I love mine.
Heres a 6" barrel next to my 10" mkII.

I went with the NEOS in 4.5 (Base Model) with el cheapo red dot courtesy of China Mart (BSA).  I was looking at a 22/45 but twonami convinced me with the reliabiliyt and takedown part.  Is there any particular area that is better to mount the sight.  I know I have my Aimpoint as far forward as possible on my AR, but on a pistol is balance more important?

I mount all my pistol reddots over the hand. I tried forward on the Beretta but I wasn't crazy about how it felt.

Went to the range today with my new 4.5" Neos with the China Mart BSA red dot.  Sighted in and went through 300 mini-mags.  I am very happy with my purchase, and all for under $250.  ZERO problems with the pistol.  I think the only thing that keep people from it are its Star Trek looks in pictures, but in person it is a nice design.  Takedown is easy.  The overall fit and finish are very good.  Trigger is pretty decent and if thats a concern there is an adjustable trigger model.  Magazines are $13 on ebay and very easy to load.  Accurate as you can be and zero recoil.  I haven't tried a Buckmark or 22/45 (other pistols I researched) so I can't compare, but overall I'm extremely happy!  The BSA worked like a charm as well.  I was considering getting an Eotech for it, but a $350 sight for a $225 .22 plinker didn't seem logical to me.  However, now that I really like my U22, I might reward it with the Eotech.

I usually stick with the irons on mine but I have a Tasco Propoint that I put on it ocassionally. Works really well.
The Buckmark I have jams when I use the wax coated bullets after about 80 rounds but with regular ammo it works fine. The Neos dosen't jam on the coated bullets.

Hey, that looks like mine.......except mine is shorter, all black and my Berber is a different color.

Quoted: Hey, that looks like mine.......except mine is shorter, all black and my Berber is a different color.

The color is washed out in the pic. It's a couple shades darker