Robinson Arms make their M96 rifle in a variety of configurations, including a top fed bren style.

M96 Top Feed

The Top Feed or “BREN” transformation of the M96 can be done with no modification to the M96 receiver. The rear sight of the M96 rifle is remove and the lower receiver is attached where the rear sight was. The handguard is switched to the other side of the receiver. Two additional parts are necessary: a receiver cover with an offset rear sight; and a barrel with an offset front sight.

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The BREN with its 30 round magazine extending out the top of the receiver could easily accept a 30 round magazine. The operator could shoot prone or from a fox hole while keeping a very low profile and without the magazine being ground into the dirt. Addtionally, the top fed rifles also benefit from more reliability because gravity aides in feeding rounds instead of against feeding rounds in conventional bottom fed rifles.

It looks cool. I am not sure if they still make the top feed kit.

More info here.