i have a pair of those lights. first used them on paper books, and then on my e-reader. but e-reading using them, i didn't find it very pleasing, due to some glare, plus not enough focus, but nothing that you can't manage. for a pittance, the clip-on light is a good makeshift option, even if it carries some (minor) niggles. however, for outside-reading, a basic e-ink reader could again disappoint! experienced that too. though no one 'plans' to read outside/under daylight conditions per se, but at times, or, many-a-times, we just carry our e-readers for a travel/commute/picnic/leisure-trips, and then we take out the e-reader to quench our reading-thirst, is when we realise the uneasing-issue facing us.
don't let budgetary-woes bog you down. you don't need to spend much more than what a basic e-reader would cost you. have a look at this:
Kobo GLO Black | eBay
Kobo is also an acclaimed (Japanese) brand. check a few reviews of this model. the MRP is/was supposed to be 10-11k. moreover, its now not easily available at retail-stores (or perhaps no more available), or on the portals of authorised resellers here. though for the above listing, no discount-coupon might be applicable, as i had checked it about a month back, and at that time, this particular listing was not covered under rebates.
IMO, you should also be willing to consider used e-readers. there are many people who buy them thinking that they have accumulated a lot of ebooks & ezines, and will spend a lot of time reading them, but after buying an e-reader, the interest gradually wanes, and the e-reader then lies disused. there are many over at TE with e-readers (there had been a GO for NST too there sometime back), and am sure you could find one who would be willing to sell his e-reader to you. for instance, a friend and a member there had a sparsely used Kindle PW to sell and had asked me sometime back (though not listed for sale on the forum). if you're interested, i may ask him the status of his e-reader.
else, the model linked to above is a good & recommended, reasonable & affordable option for for a new-product purchase (though yes, it has a touch UI).