Between the Toshiba 32c3035, the Sony 32s3000 and the Panasonic tx32lmd70, I would definitely choose the Panasonic. This is because, having seen all of these tvs in action, I believe that that the Panasonic has the best picture quality, with SD sources especially, and also HD. Speaking of HD, even though you say that you're not going to buy an HD player at the moment, you mention that you may in the future and if that is the case then you need to make sure your tv will accept a 1080p feed at 24 frames per second (also known as 1080/24p). The Panasonic tx32lmd70 will accept such a feed, unlike the Sony 32s3000 which will only take 1080/50i or 1080/60i at the most which means it just isn't adequately futureproofed. The Sony will still be compatible with Blu-ray or HD-DVD, but as it cannot handle 24fps then you will end up with an image that judders or stutters when there is motion, such as a camera pan. I'm not completely sure where the Toshiba 32c3035 stands with regards to 1080/24p - I think it will accept, however, I do not think the performance of this set is up there with that of the Panasonic, or even the Sony, apart from when playing back 1080/24p material, obviously.
So, I would absolutely recommend the Panasonic out of these three tvs. This is not just to do with the 1080/24p issue, important as that is, but is a lot to do with the Panny's overall performance in terms of picture quality. It really does offer a very good, stable picture, whether that's with it's onboard Freeview (or it's analogue) tuner, upscaled DVD or native high-def material such as Blu-ray, which it really shines with. The Sony mostly offers good picture performance aswell, but the lack of 1080/24p really does let it down. However, even if it wasn't for the 1080/24p issue, the Panasonic would still have a better picture overall.
In fact, the only problem with the Panasonic tx32lmd70 is occasionally with fast motion it can have a tendency to blur or lose resolution. This is only a small problem which is rarely noticeable, but if after viewing the tv for yourself, you find it bothers you, then you may want to try the higher spec Panasonic you mention - the tx32lxd70, which has a 100Hz thingy which basically doubles the frame rate to make motion flow more smoothly. This is actually the only difference between this tv and it's less expensive sibling the tx32lmd70, apart from the more expensive model's slightly higher claimed contrast ratio of 8500:1 compared to 7000:1, which isn't a huge difference. How important these two features are is something that you will have to decide for yourself. In my opinion, the cheaper tx32lmd70 is nearly as good as the tx32lxd70.
The other tv you mention is the Sony 32d3000 which is a very good tv, and unlike it's cheaper sibling, does accept HD material at the optimum 1080/24p. Again, though, I think that it's picture is beaten by it's Panny rival, the tx32lxd70. In fact I probably prefer the cheaper Panny (tx32lmd70) to the more expensive Sony 32d3000. I'm getting confused myself writing this!
Basically, if it was up to me I would pick either of the two Pannys which are both as futureproofed as you could possibly want, but more importantly for you, they excel at standard-def aswell. Having said this, different people prefer different characteristics of a picture, and for this reason you may prefer the picture of the Sony 32d3000, so make sure you demo that one too.
I know at the beginning of your post you said that you are not planning on getting an HD source in the near future, but you also said you may get one eventually - for this reason I would say that you must get a set which is compatible with 1080/24p. So to conclude, it's between either of the two Panny's and the Sony 32d3000. I would go for the Panasonic tx32lmd70. You must see these three tvs in action before you decide which to buy, so make sure you visit a shop even if you plan to buy online. Good luck mate.
Facebook
Twitter
Instagram