You have to take the back seat out to get to them. I have done LOTS of suspension work on my solara over the years. First year I owned only thing you could buy after market was Eibach pro-kit lowering springs (Fixed at 1.6'') and "preformence" struts were KYB or Tokico. I had both at one point KYB lasted about a year and 1/2 then the rear ones started softening too bad, replaced with Tokico they lasted about a year. Finally Tein came out with coilovers for the solara, best investment ever. I have had them for about 3 years now, no problems, MUCH better handling/look everything night and day difference.
So my advice, save money for longer and do it right the first time and get coilovers. If you're really not into that much then I'd go with the KYB struts, they are cheaper then Tokico and will last about as long. If you don't drop your car you'll be fine with the struts in the long haul.
Hope this helps!