Lens/ Equipment Advice Please

[leezer3]

So, I feel the need to pick a few brains

First off, I'll detail what I've got at present:
Canon EOS 400D
18- 55mm kit lens
28- 105mm f4.0/5.6
75- 300mm f4.0/5.6

I use these for railway photography generally. As such, my most used focal length ranges tend to be 60- 100mm, followed by 18mm wide angle, which means that most of my images tend to be taken with the 28-105mm, with the 18-55mm on wide-angle duty and the 75-300mm for anything requiring a closer zoom.
The 28-105mm cost me £20 secondhand, and while there's nothing actually wrong with it (Optics are perfect, no major dust either), it has zoom creep and a nasty wobble when fully extended.

I'm rambling a tad, so the question:
I'd quite like to replace the 28-105mm with something a little more solid. Ditching the 18-55mm would be nice, as would IS, but neither of these is essential. I also want the option to mount a circular polariser to the replacement with no fuss.
My current shortlist appears to these two:
Canon 17-85mm f4.0/5.6
Canon 18-135mm f3.5/5.6

Advice please?
A reccomendation on a relatively cheap, but good quality circular polariser would be appreciated too

 

[StewartR]

It would help if you could give some indication of your budget....

 

[Chunkey Monkey]

The EF-S 18-135mm 3.5-5.6 IS is pretty good for the price but as stated whats your budget ?
if you can stretch to it look at the EF-S 18-135mm 3.5-5.6 IS STM this has a faster focusing system and sharper image quality or even better the EF-S 15-85 an extremely good lens but costs more and may not have the reach you want.
The 17-85mm isnt that good really has distortion and CA at the extremes

 

[leezer3]

Trying to figure out the difference between the STM and 'ordinary' version of the 18-135mm has just given me a headache
Is there any visible difference, or would I just have to rely on the STM statement in the name where the number of blades aren't mentioned?
STM versions seem to be ~£250 as whitebox splits from the HK sellers, as opposed to ~£210 for the non-STM variant.
(If it's a new whitebox split, can I assume it's a STM version, or are the older ones still being supplied?)

Budget would end up being £300 at the max, although that could possibly be supplemented by getting rid of the 18-55 and the 28-105.
(Sorry, should have mentioned that more clearly, rather than inferring through the lens choices )

For what it's worth, the 15-85mm is an interesting choice which I hadn't considered, but probably not the right one.
I'd rather be changing lenses at the short end than the long end, and it's definitely more than my comfort zone in terms of price point.

 

[arwesa]

wex should have a nice 24-105 L I just sold them.... with selling your other two and your 300 you might get somewhere near?