i would personally recomend for that budget the MTX THS502 13cm components
they are very well priced at 89.99 RRP, and they have a very compact crossover and the tweeters are silk dome, so u get a very nice smooth sound, alot of manufacturers use aluminium tweeters in this budget range which i find to 'hissy' and harsh to listen too.
and ideally you should always mount the tweeters as close to the midrange as possible to prevent too much seperation of sound, so i would say to mount them in the upper dash is a complete NO NO!! if the door cards are not a good place then fit them in the kick wells, fire the tweeters upwards and u will be supprised with the results, the sound will be clear and appear to be coming from the front screen, have fitted alot of comps like this and works very well,
hope that helps
steve