for cell fractionation we're using a kit (Plasma Membrane Protein Extraction Kit) from MBL International Corporation that works quite well. Hope it's suitable for you
we're using a kit from fermentas (know Thermo fischer I think -e.g. NE-PER Nuclear and Cytoplasmic Extraction Reagents). These kits are available for different purification steps like membrane, nuclear or cytosolic fractions and the only centrifuge you need is a benchtop microfuge.