This is a little complicated.
On the modular motor, the RH manifold has the thin metal gasket. That can and should be re-used unless it looks bad. They hold up well. To my knowledge, no exhaust company includes this gasket with their midpipes. They are available from Walker and Ford i believe.
On the LH side the metal sleeve is needed and provided by Pypes for Pypes products. The UPR X-pipe (although produced by Pypes) is totally designed by UPR and I do not know if the sleeve is needed or included in their kit. You should contact UPR for the answer.