house septic help!

my house is having a back up problem from the poopy tank and its been determined that the leach feild has failed.

so my thought process is : i have heard some negative feedback on the newer rockless infiltrator systems and i always thought the best way was the old fashioned rock and pipe leach feild

so my question is: i got a quote from a company for $2500. for an infiltrator system ....should i trust that ....or look for a company that will do a rock and pipe system like the original system was??

History: my house was built in 1975 and its the all original system ....great big concrete tank which i have reason to believe that its a dual chamber tank ....we have determined the tank is good ...i have documents showing it was pumped regularly all its life.
two years ago i replaced the PVC pipe from the house to the tank so i know thats good.

behind the tank the i have lots of open space to go out with the new leach feild and im at least 150 feet away from my well pump house as per code.

any advice??? any knowledgable input is greatly welcomed bcoz im just getting educated about all this and this my first time with a problem of this nature ....but im trying to do my research first