Looking for construction attorney for collections

Hello , I have a construction materials supply company here in miami and I'm looking for an attorney that has experience in foreclosing on construction liensOur company is 50 years old and we presently have an attorney which we have been working with for years with great success but we are looking for someone new because his workload has gotten heavyWe have had great success because we know the lien law like the back of my hand and we do the NTO's flawlessly and we post and cert. the liens at the jobsite and we keep exquisite notes and data on the eventsI would like to know how you chargeDo you work on a contingency basis or hourly