Hi Flintus. The Arcadia lamp will def work though this has a relatively narrow beam. I have used that kind of lamp and they are good except the area covered by the footprint might not be the best for larger tortoises. With hatchlings and juveniles the Arcadia halogen will work well, just be aware that the area covered is quite limited.
But you don't need to spend the extra to get a halogen lamp that works well for tortoises. A lamp like this one is cheaper and basically the same:
http://www.bltdirect.com/hi-spot-par-25-80mm-dia
The Every Ready lamps on your other link are probably not great in this application. The heat and light is dispersed very widely and isn't a large amount to begin with. I haven't tried the Ever Ready, but other similar lamps seemed just like a 'normal light bulb' but longer lasting.
A good alternative to a lamp like the Arcadia is a halogen with higher power but mounted further away obviously. Such as this one:
http://www.tlc-direct.co.uk/Products...FY_MtAodDi0A_g
The advantage of the 'outdoor' lights is that you get a much bigger footprint of heat and light but I don't think any of them could be used indoors without a dimming stat.